[GRASS-dev] scale and offset in raster maps

[andrea antonello]

Probably I wasn't clear enough, or better don't know exactly how to
explain this.
I'm not talking about resampling, btu instead of threating of a single
value. In scientific data often you could store integer maps for
several reasons and there is an offset and scale value that have to be
applied to get the usable physical floating point value of the map.
Scale and offset are defined in formats as for example netcdf and I
thought I saw this also in GRASS in the past.

Andrea


On Mon, Sep 15, 2008 at 9:29 AM, Glynn Clements
<glynn at gclements.plus.com> wrote:
>
> andrea antonello wrote:
>
>> I am pretty sure in the past I saw somewhere in the raster format the
>> concept of scale and offset, by which the data are math-transformed
>> when read.
>> I went throught the developers manual but wasn't able to find it.
>> Can someone please tell me if the scale-offset tranform is something
>> supported in the format or if I am just remembering wrong.
>
> Raster maps are resampled based upon the current region. This is a
> scale-and-offset transformation; there is no rotation or skew.
>
> --
> Glynn Clements <glynn at gclements.plus.com>
>